


The Taste of Ketchup

by Purple_Stargazers



Category: Undertale (Video Game)
Genre: F/M
Language: English
Status: In-Progress
Published: 2015-12-01
Updated: 2015-12-04
Packaged: 2018-05-04 09:00:15
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,668
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5328374
Author URL: https://archiveofourown.org/users/Purple_Stargazers/pseuds/Purple_Stargazers
Summary: <blockquote class="userstuff">
              <p>After numerous resets Frisk cannot take it anymore, after being invited to San's lunch break frisk makes their move. *Disclaimer* Frisk is 24 in this fiction.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Hello! This is my first work and I'm really excited about it, I may have some errors in there because I couldn't wait to post it, so if you see a few errors please let me know where so I can fix them! Thanks!

“Hey kid, how about you join me on my break?” Sans says happily.  
You nod in excitement with blush sprawled across your face.  
“Here, follow me, I know a short cut.” Sans says while grinning.  
You follow.  
You both go to Grillby’s, Sans sits down next to you, and asks, “What will you have kid? Fries or Burger?”  
“Fries, please.” You reply softly.  
“Okay, I’ll have the same, then. Grillby two orders of fries.” Sans orders.  
After two minutes of you staring down at your lap blushing, Grillby brings back the food, piping hot. You stare at the fries for a second, but Sans breaks your train of thought.  
“Hey kid, do you want some ketchup?” Sans says while winking.  
You know exactly how this is going to play out, yet you want it this way.  
“Yes!” you reply.  
Sans tips the bottle over and all the ketchup falls all over your fries.  
“Ah, sorry kid, you ca-“ Sans begins.  
You interrupt him and softly grab his hand after he placed the bottle down. You push his fingers down to have his index finger out like he was pointing to something. He looks at you with a puzzle on his face. After doing so, you gently press his finger into the fries drowned in ketchup.  
Slowly you bring it up to your face and suck on his finger, you don’t break eye-contact. You swirl his finger around in your mouth, affectionately bobbing your head up and down, in a sexual motion. Sans, at this point stares at you with wide eyes, his face being engulfed in a light shade of blue. You’ve never seen him this way, but you love it. As you continued to suck his finger, your face began to turn a soft shade of pink. You begin to get really into it. Too into it. You began to lick the palm of his hand and suck on every finger on his hand, seductively of course. Sans face is a deep shade of blue, now. But, you keep going. You continue to caress his hand with your tongue, then pull it to rub against the cheek of your face. You look down at his hand for a second, and look back at him with a sexual glare. You knew what you wanted. You looked at Sans completely speechless with his mouth hung open. His right eye began to glow, and something below the bar table glowed too, it seemed like something peaked in his shorts. You seem to be the only one to see it since you’re sitting so close to him. You slowly take your free hand, and pace it over the glowing crotch. His pupils dilate to a smaller size. You begin to caress his member slowly while continuing your licking motion. Sans stops looking at you, to see if anyone else is seeing what he’s seeing. No one noticed. They were so engulfed with what they were doing that no one noticed. Even Grillby, he sat at the other end of the bar and washed glasses, and the sound of jukebox was loud as always, so no one could hear the wet sound I was making with my lips. You decide to stroke him harder, Sans lips shot open with a yelp, “Ngh!” You continue, but look at sans with a smile on your face, his face is covered in blush. You speed up, Sans couldn’t take it any longer, so he snatched his hand back and hunched over, he tries to cover his crotch up, but with your now free hand you grab his two hands to stop him. You go into his shorts, grab his member, and began to stroke violently. Sans gasps. A sweat drop is forming on the side of his skull. He can’t take it anymore. You jerk him off faster than ever before, and he cracks. He loudly orgasms, “Ahhhh~!” and cum gushes on your hand. Luckily no one heard him, due to the loud music from the jukebox, and the chattering patrons at the bar with sounds of clinking glass. You slowly slip out your hand. You look him dead in the eye as he catches his breath and sucked off the white liquid on your hand. He stares at you, growing bluer by the second. After you finish, you take the money out of your pocket and leave it on the counter. You’ve grined through the areas before hitting this area, so you have about 520,000 dollars, you did this mostly for the Temmy armor, and to impress Sans. You knew the question about the money would come up, but you were prepared. You stood up, winked at Sans and left. Within Sans pocket you left him your number. You continue on your journey, thinking about what just went down and you can’t stop blushing. Determination.


	2. Detemmination

**Summary for the Chapter:**

> Fisk continues their journey. They go shopping in Tem Village.

**Notes for the Chapter:**

> Hello! I am back! I am presenting you with the next chapter enjoy! I already have the next chapter done, if you'd like to read it leave a comment down below and I'll decide if I'll post it tonight or tomorrow. Have an awesome day!~

On the way to finish your journey, you stop by Tem Village. You greet every tem and bob on the way to the Tem Shop. You stroll in and greet Tem. She’s excited as always. You grab your stash of cash and dish out a 1,000 dollars to send her to “Cool leg”. She leaves, and comes back with her graduation cap. Now you can buy the Temmy armor! You slam your money on the table and she takes it gleefully. You receive your armor and don it on your body.  
Then suddenly, she leaves again. You look at her questioningly. This has never happened before in all your other runs. Well, then again, in your other runs you never bought it for the highest price either. So you wait. She comes back with a diploma this time, and 2 other Temmies. They all looked identical, except all their shirts were different. They also all sold different items. The Temmy in the red shirt sold clothing, while the light blue shirted Temmy sold armor still, and the yellow shirted Temmy sold potions. Shocked by the two new additions, you shake it off and continue shopping. You decide to talk to the red Temmy.  
“Um… Hey Tem, what are you selling?”  
“Tem sells a lot, check out shop,” the red Tem replies.  
You then remember how vaguely Tems talked, you wonder what cool leg even taught them. You check out the list in front of Tem of what they sold. You should’ve done that in the beginning. You analyze the list.  
Tem’s Clothing Store  
Skinny Jeans  
Leggings  
Short Shorts  
Crop top  
Tight red dress  
Wedged converse  
Red high heels  
Backpack  
Plain black t-shirt  
Over-sized Hoodie  
Black lace up boots  
Pink lingerie panties with matching bra

You glance over the list a few times and place your order.  
“I… Uh… Would like to purchase your… uh… everything.” You say awkwardly.  
Tem nods and says, “That be 9,000 dollars.”  
You take your money and shove it to her, she carefully packs the items in the backpack that came with it and hands you the goods. After you take the bag you put it on your back and go to the yellow Tem.  
This time you’re ready. You instantly try and grab the list, however, this Tem grabs your hand and says, “How rude of you sir, can you not say a simple hello to me?” Shocked you take a step back, adjust your self and say, “My apologies, what is your name?”  
“My name is Bob.”  
“Bob? The same one from outside the shop? How’d you get here, and when did you change shirts?”  
“You see, when you payed for that over-priced Temmy armor, Tem came to me and took me and a friend to “cool leg” with her, with the left over money from that item we went into business together.”  
“Ah, I see, okay. Well, what are you selling?”  
“I am selling potions.”  
“What kind?” You ask quickly.  
“I only sell what you need. I have tons, however, giving you every potion I own would make you dangerous. So as you need things come to me and ask me for that specific potion.”  
“Hm… Okay. I would like a potion to capture someone’s heart.”  
“Nope, we’re fresh out of that how about a potion that will make your body grow more? It’ll be 500 dollars.”  
At first you questioned it. Your body is aging pretty slowly after every reset. You’re 24 now, however, your petite body doesn’t show it. Your small up top and a little heavy on bottom. You think this over. A sexier body will get him to notice you… You decide to buy into it, at least give it a chance you thought. “I’ll take it.”  
Bob raps up the potion and waits for the money. You grab your money and slide it over to him, and quickly snatch the bottle. It was heavy and large, it was like a jug of fruit punch. You begin to head out.  
“One more thing before you go kid, that potion can be permanent, if you mix it with alcohol it’ll become permanent, so test out your new body and decide what you want to do. Until then, come back when you need anything.”  
You nod with a smile and continue out the door. You save and continue on your journey now with some new clothes, potion, and armor. You’re ready for anything coming your way.  
You go through the lands, and go through all the normal escapades. You go to Hotland, and have finally reached Sans’ hot dog stand. You stroll up to him, and as you come close to him, he becomes a soft shade of blue.  
“H-hey kid,” he says softly. His eyes dart around.  
You look at him with a smile on your face. “Hey, Sans. How are you?” You keep your cool, it’s too bad you can’t go behind that stand.  
“Nothing m-much, kid… How are you?”  
“I’m fine just can’t wait for later on tonight.” You reference to the dinner tonight, but so lightly, that Sans didn’t catch it. That’s fine of course he’ll get it later.  
“Uh… any way, kid would you like a hotdog?” Sans says bravely.  
“Only if it, glows.” You say while biting your bottom lip and looking at him up and down.  
Sans is wide eyed again like before and his face is a deep shade of blue. You caress his face, and blow a kiss. You take out money, place it on the counter, and take the hot dog out of Sans’ hand.  
“You wouldn’t happen to have ketchup would you?” You say smirking.  
Sans then stared at you with dilated pupils and a face color as deep as the ocean.  
You decided it was enough teasing, “I’ll see you later… Sans~” and continue on your journey.


	3. Dinner for Two

**Summary for the Chapter:**

> Frisk goes on a dinner date with Sans.

**Notes for the Chapter:**

> Hey! Here's the next part, leave a comment below please, I love reading your guy's comments! If you want another chapter let me know down below, and I'll start working on it, until then enjoy this chapter!

After going through the different areas, it’s time. Before heading into Mettaton’s hotel you go back behind their alley way and buy the mystery key off of Catty and Bratty. You pocket the key. You see a backdoor entrance to the hotel and enter. You buy hotel room to change in. After purchasing one, you take the key and walk in to the room. Setting your backpack down. You rummage through it to find a good outfit to wear. You pull out the leggings, wedged converse, black t-shirt, baggy hoodie, and pink lingerie. You strip down put all the pieces on, in the right order of course. You put on the pink panties first, they’re a little big on you but whatever. You see the matching bra, but decide against using it.  
After that you put on the leggings, they fit better, however they are stretchy so they’re really comfortable. You enjoy the softness of the pants. You then put on the black t-shirt and then put on the wedged converse. They’re a little big on you as well, you just move on. The final touch you put on the EXTREMELY baggy hoody on. You look in the mirror you look really baggy. You’re drowning in your hoodie. Despite this, you waltz outside, and encounter Sans, who then asks you out to dinner. You accept, and take the short cut he has. You both sit down at the Mettaton shaped table and look at each other. Sans seemed still flustered by what you did to him. You take this chance to place your backpack by your chair and set the jug of potion right next to the table leg.  
“Thank you for the invitation, you’re so sweet.” You say with a smile.  
Sans smiled and blushed at the same time.  
“I brought you out here tonight to talk to you about a story.”  
You knew this was about Toriel and his crush for her, however, you’re determined to crush his crush for her and replace her with yourself.  
“Before that Sans, I wanted to tell you how much I liked you…” You blush softly.  
Sans starts to blush again.  
“I wanted to tell you… Tell you… that I want to spend the rest of my life with you. You’re so amazing, adorable and funny, your puns slay me every time. The more puns you say just makes me want to kiss you. I know this is quite sudden, however, I’ve spent years with you, and you may ask why and the answer is through the reset. I know you know what that is.”  
Sans snaps the blush off his face, parts his lips, then closes them again.  
He speaks, “So… You know, huh? Well, do you remember the timelines?”  
“Of course I do, every time I reset, my… uh… sexual frustration for you got worse and worse, but this timeline, I’ve made my move,” You say softly.  
Sans blushes. “So what are you going to do now? I like the outfit you’ve got on.” He chuckles. It seems that he finds your outfit ridiculous. It’s probably because it’s so baggy. You notice his glance, and chuckle, and ask, “Does my body turn you on?”  
Sans chuckles again, “You’re funny kid, your hoodie looks nice.”  
You laugh, as well. But you were prepared for this. You pull off your hoodie slowly to accentuate your soft hair. And ask Sans for the wine glass sitting in front of him. He complies and passes you the glass.  
You set it down next to you, and take the jug from under the table and pour yourself a tall glass of that potion Bob gave you. You hold the glass in your hand.  
“Before I drink this… Do you think I’m sexy now?” You say softly.  
Sans chuckles again, “You’re too small for your clothes, kid. You’re cute.”  
You look at Sans, then sip down the whole wine glass. Not a drop was spilled.  
You look at Sans deeply, as he still has the signature smile on his face. You stand up, and a pain in your stomach began to ache. You grunt in pain, and Sans looks at your worried. Your body began to tremble. Sans began to get up and try to help but you hold your hand up to him and he stops and sits back down, a bead of sweat coming down his forehead.  
“Ah!~” A sensual moan came from you, embarrassed you tuck into a ball, but then suddenly, you get back on your feet and you feel your body stretching and growing. Some parts of you swell up, all at once. It was painful, but worth it in the end, you could finally no longer feel like a kid, and finally feel your real age. You became taller, and your thighs became thicker. Your leggings became full of your soft voluptuous thighs. You also felt your bottom becoming bigger. You twisted your body as far as you can to see how much it’s grown. You accidentally turn your back towards sans and you could feel his eyes grazing over your plump bottom. Realizing this you turn around quickly and look at Sans with a blushed face.  
Sans Blushed as well. You move your now long arms over your long legs to hide them. You then notice that your black shirt had become a crop top. You thought the nightmare was over, however, one last thing on your body grew. Your breast. Your breast grew at such a quick rate the shirt ripped halfway down, close to expose your nipples. You regret not wearing the bra. You stare at your new found breast, your nipples are making peaks in your shirt. You then glance up at Sans. His mouth is hanging open, and his nose… I somehow bleeding?  
“So… Do you think I’m sexy now?” You ask sensually. You strike a dramatic pose.  
Sans is speechless. You wipe off the items off the table and put your body on it. “Do you want to feel my supple body?” You inch closer and whisper in his ear. “Do you want to feel inside of me?”  
Sans looks around wide eyed and blushing. You grab his hand slide off the table and lead him out of the restaurant. You’re taller than Sans now, it feels nice to see the tables turned. Sans now was at the height of your hip. You made sure not to sashay too hard or else your thick hips would bump Sans. You both stroll through the different areas, you noticed how San’s eyes wandered on your body constantly. You decide to pick him up, he’s quite light, so light that you accidently nuzzle him into your breasts. Sans face turned blue again. Noticing this, you kiss him on the forehead and continue to cuddle him against your chest. You continue to walk down the road and finally you arrive in front of the pink house next to Napstablook’s. You knew who this house belonged too, however, your too embarrassed to go to Sans’ house where Papyrus could be.  
You take a deep breath and unlock the pink house, step over the diaries, and lay Sans on the bed.  
You ask him, “Are you ready?”  
Sans looks deep in your eyes, and says “I am.”  
You walk towards the door and turn the light off. It became pitch black. You walked carefully around those diaries back to the bed, and feel around for him until you find his leg. You caress his leg and rub his inner thigh bone. Soon he begins to glow again. This gave you light to see where he is. While rubbing his thigh, you kiss him lightly on his lips, and keep kissing him until he lightly opened his mouth. You insert your tongue to find his tongue. It felt warm and inviting. While you caressed his thigh your kissing became more and more passionate. He began tugging on your hair, you got rougher during your make out session the sound of wet sounds filled the room. Both of your faces were hot. Sans right eye began to glow and his member popped in his shorts again. Sans looked down and covered his face in embarrassment. You slowly move your head down his body leaving little love bites all over his ribs. You reach his pelvis, and remove his shorts, and boxers. You slowly took his member into your mouth. Sans gasps. While he was inside your mouth you move your tongue around in a circular motion and bob your head up and down.  
“AH~,” Sans yelped.  
You move faster, and your face became a deeper shade of red.  
“Ngh! Ah~” The moans coming from Sans won’t stop. And you love it. You continue to suck him off, the more you sucked it was like you were trying to taste him. You wanted all of him.  
“Ah~ Ahh~ I-I’m go- gonna c-c-cum,” Sans huffs out.  
You stop sucking for a second, and remove your clothes quickly. You then climb over sans and position yourself over his member. You slowly press him inside of you. You both gasp. His member was so thick and long, you wasn’t sure if it would fit. You keep pushing and it finally fits. You then began to rock your hips in a rhythm. Sans held onto the sheet while you road on top of him. His eyes closed and face a deep blue. You keep thrusting at your pace, however, sans couldn’t take it anymore. Sans pushes you off the top of him and he hangs over the top of you. You blush deeply waiting for him to make his move. He then lifts up your legs and plunges deep into your vaginal walls. You moan loudly and uncontrollably. You reach out and grab the back of Sans, and hold on tight. Sans began to thrust deeply at crazy speeds. You throw your head back with your eyes rolled back so far only the white of your eyes can be seen. Your orgasms are assaulting your body and won’t stop.  
“Ngh! Mmmm~ Ha! Ha~ Ha~ S-sans! Ugh~! Oh~ Sans!” You yelp loudly.  
Sans began to have that signature smile on his face again.  
Sans began to blush deeply while hearing you call his name.  
“Ugh~~! Hah!!~ Oh~! Please give it to me harder Sans! Harder!~ Please, I want you so bad~” You moan.  
Sans goes harder and deeper than ever before, you can feel the hilt of his member inside of you. You can’t take anymore, your mind is foggy and your so close you bight your lip.  
“I’m cu-cumming!” Sans yells.  
“Please! Ugh~~ Cum so hard in, ngh, me I want my kidneys to feel it!” You embarrassingly say.  
Sans blushed really hard after hearing you say that, and let out one last loud grunt and came inside you. You orgasm one last time, as he came and your body convulsed in his arms while you road it out.  
“Ah~” you let out one last moan.  
Sans slid out of you and his cum slowly came dribbling out. He rests himself on top of your body and you kiss him patiently. You both fall asleep in each other’s arms. Your heart is filled with determination.


End file.
